71 TQ info

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Ceedawg

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I’ve been reading up on the TQ and for racing the 71 is better, for street use the 72 and up are better. Can the later carbs be set up or changed to the 71 style? Does anyone have a diagram of the fuel-air channels to compare (I have the 72 and later)? This will go on a Stocker 340
 
Perhaps one of my videos will help out.
If not, let me know. I’ll make another short video.

In short, you can not convert.
 
Click below



upload_2022-7-10_19-55-14.jpeg
 
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I’ve been reading up on the TQ and for racing the 71 is better, for street use the 72 and up are better. Can the later carbs be set up or changed to the 71 style? Does anyone have a diagram of the fuel-air channels to compare (I have the 72 and later)? This will go on a Stocker 340
The 71 are totally unique. They are faster on our stockers by 1 to 2 MPH
The only carbs that are nearly as fast are the "Super Quad" 9800 carb. The next best
are 9801/9810/9811.
The reasons are too complicated to go thru hear and only of interest to Stock and Superstock Racers.
The all require modifications to run in these classes competitively.

Google: John Irving Drag Racer
 
71s mixture screws meter air instead of raw fuel IIRC. Opposite of what most other carbs do. Dont know what needed to be fixed on 72's but they were made opposite on metering. Something like that.
 
Thanks for the answered. What is the 71 numbers to look for?
 
4972 std 4973 auto. they are one step down from original hemi carbs for prices so be prepared.
I paid $1600 for a set of 1966 Hemi carbs last year
 
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71 TQ is unique and prone to issues. 72 and up were redesigned to fix the issue...

Many of the 71 carbs were replaced under warranty by 72 carbs by the dealers.
This was because of drivability issues!
This helps to explain why they are hard to find.
I do not recommend them for a daily driver

The best performance calibrations were the 9800 followed
by 9801/9810/9811 all aftermarket Super Quads.
Cores for those can be found $200 to $300.

The emulsion tubes are a restriction to metering on every
OEM supplied Thermoquad for racing and nearly impossible
to change or drill without ruining them completely!

I have been racing these since new.

Google: John Irving Drag Racer
 
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Many of the 71 carbs were replaced under warranty by 72 carbs by the dealers.
This was because of drivability issues!
This help explain why they are hard to find.
Yes indeed. We bought a 3000 mile original 1971 Demon and it had already had the 71 carb removed and a 72 on it! The intake looked like it had leaked fuel all over...
 
No Sir = those are 1971 340 production carbs.

The Competition Series are 850 and 1000 race carbs
that are completely different animals. (I have been
hoarding one of each).
 
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Picked up a 71 at Carlisle just now for $225 4973a
 
Found another for $250 I might get too, the needle is stuck and won’t go in, not sure if that’s an easy fix?
 
Easy fix

You are getting bargains

I paid nearly $500 for a used one a couple week
ago that was similar!!
 
One guy wants $850 he knows what he has, I played dumb while he told me all about the carb.
 
One guy wants $850 he knows what he has, I played dumb while he told me all about the carb.
Oh darn! Well, it was worth a shot right?!

The idle mixture screw should seriously not be forced to turn. The way I did a stuck one a long was back was to lightly tap the lower body 1/3 while apart with a small hammer to try induce a little shock to it. This was done a lot before and during a lot of oiling and rust disintegrator was sprayed on both sides of the screw. In the barrel of the effected screw is a slot of idle. Those slots were generously given ample amounts of liquid.

Remember that is a steel screw in an aluminum body so great care and patience should be used. I’ve screwed a few up on AVS & AFB carbs before. It’s easy to do, screw it up. Take your time.

Or contact Dana I think his name is, @ “Woodruff carb” to have him look at it. He does advertise here & is a FABO member before he got into this.
 
Oh darn! Well, it was worth a shot right?!

The idle mixture screw should seriously not be forced to turn. The way I did a stuck one a long was back was to lightly tap the lower body 1/3 while apart with a small hammer to try induce a little shock to it. This was done a lot before and during a lot of oiling and rust disintegrator was sprayed on both sides of the screw. In the barrel of the effected screw is a slot of idle. Those slots were generously given ample amounts of liquid.

Remember that is a steel screw in an aluminum body so great care and patience should be used. I’ve screwed a few up on AVS & AFB carbs before. It’s easy to do, screw it up. Take your time.

Or contact Dana I think his name is, @ “Woodruff carb” to have him look at it. He does advertise here & is a FABO member before he got into this.
Thanks, most if not all of the screws are tight and won’t bulge. I’ll let it sit in evaporust for a couple days when I get home.
 
Also, heat the area with a propane torch & dribble ATF over the threads to help break the rust 'seal'.
 
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